package com.greedy.service;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.StrUtil;
import com.alibaba.fastjson.JSON;
import com.greedy.bean.dto.ScrollResult;
import com.greedy.bean.dto.UserDTO;
import com.greedy.bean.pojo.Blog;
import com.greedy.bean.pojo.Follow;
import com.greedy.bean.pojo.User;
import com.greedy.constants.SystemConstants;
import com.greedy.interceptor.UserHolder;
import com.greedy.utils.Result;
import lombok.extern.slf4j.Slf4j;
import org.n3r.eql.Eql;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ZSetOperations;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.*;
import java.util.stream.Collectors;

import static com.greedy.constants.CommentConstants.*;

/**
 * @Author: Yanxy
 * @Date: Created in:2022-12-25
 * Description: 博客
 */
@Slf4j
@Service
public class BlogService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    public Result saveBlog(Blog blog) {
        // 1.获取登录用户
        UserDTO user = UserHolder.getUser();
        blog.setUserId(user.getId());
        // 2.保存探店笔记
        Integer isSuccess = new Eql().insert("saveBlog").params(blog).returnType(Integer.class).execute();
        if (isSuccess != 1) {
            return Result.fail("新增笔记失败!");
        }
        Long blogId = new Eql().selectFirst("getBlogId").params(blog).returnType(Long.class).execute();
        blog.setId(blogId);
        // 3.查询笔记作者的所有粉丝 select * from tb_follow where follow_user_id = ?
        List<Follow> follows = new Eql().select("getFollowUserIdByUserId").params(blog).returnType(Follow.class).execute();
        // 4.推送笔记id给所有粉丝
        for (Follow follow : follows) {
            // 4.1.获取粉丝id
            Long userId = follow.getUserId();
            // 4.2.推送
            String key = FEED_KEY + userId;
            stringRedisTemplate.opsForZSet().add(key, blog.getId().toString(), System.currentTimeMillis());
        }
        // 5.返回id
        return Result.ok(blogId);
    }

    public List<Blog> queryMyBlog(Integer current) {
        // 获取登录用户
        UserDTO user = UserHolder.getUser();
        // 根据用户查询
        HashMap<String, Object> map = new HashMap<>(3);
        map.put("userId", user.getId());
        map.put("currentPage", (current - 1) * SystemConstants.MAX_PAGE_SIZE);
        map.put("pageSize", SystemConstants.MAX_PAGE_SIZE);
        return new Eql().select("getBolgOfMe").params(map).returnType(Blog.class).execute();
    }

    /**
     * 获取热点博客
     *
     * @param current 页码
     * @return 热点博客
     */
    public List<Blog> queryHotBlog(Integer current) {
        HashMap<String, Object> map = new HashMap<>(3);
        map.put("currentPage", (current - 1) * MAX_PAGE_SIZE);
        map.put("pageSize", MAX_PAGE_SIZE);
        List<Blog> blogs = new Eql().select("getBlog").params(map).returnType(Blog.class).execute();
        blogs.forEach(blog -> {
            this.queryBlogUser(blog);
            this.isBlogLiked(blog);
        });
        log.info("大白点评-首页初始化-查询热点博客-页码为：{}-热点博客为:{}", current, JSON.toJSONString(blogs));
        return blogs;
    }


    public Result queryBlogById(Long id) {
        // 1.查询blog
        Eql eql = new Eql();
        Blog blog = eql.selectFirst("getBlogById").params(id).returnType(Blog.class).execute();
        if (blog == null) {
            return Result.fail("笔记不存在！");
        }
        // 2.查询blog有关的用户
        queryBlogUser(blog);
        // 3.查询blog是否被点赞
        isBlogLiked(blog);
        return Result.ok(blog);
    }

    private void queryBlogUser(Blog blog) {
        Long userId = blog.getUserId();
        User user = new Eql().selectFirst("getUserById").params(userId).returnType(User.class).execute();
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
    }

    private void isBlogLiked(Blog blog) {
        // 1.获取登录用户
        UserDTO user = UserHolder.getUser();
        if (user == null) {
            // 用户未登录，无需查询是否点赞
            return;
        }
        Long userId = user.getId();
        // 2.判断当前登录用户是否已经点赞
        String key = BLOG_LIKED_KEY + blog.getId();
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        blog.setIsLike(score != null);
    }

    public void likeBlog(Long id) {
        // 1.获取登录用户
        Long userId = UserHolder.getUser().getId();
        // 2.判断当前登录用户是否已经点赞
        String key = BLOG_LIKED_KEY + id;
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        if (score == null) {
            // 3.如果未点赞，可以点赞
            // 3.1.数据库点赞数 + 1
            Integer isSuccess = new Eql().update("updateBolgLikedAdd").params(id).returnType(Integer.class).execute();
            // 3.2.保存用户到Redis的set集合  zadd key value score
            if (isSuccess == 1) {
                stringRedisTemplate.opsForZSet().add(key, userId.toString(), System.currentTimeMillis());
            }
        } else {
            // 4.如果已点赞，取消点赞
            // 4.1.数据库点赞数 -1
            Integer isSuccess = new Eql().update("updateBolgLikedReduce").params(id).returnType(Integer.class).execute();
            // 4.2.把用户从Redis的set集合移除
            if (isSuccess == 1) {
                stringRedisTemplate.opsForZSet().remove(key, userId.toString());
            }
        }
    }

    public List<UserDTO> queryBlogLikes(Long id) {
        String key = BLOG_LIKED_KEY + id;
        // 1.查询top5的点赞用户 zrange key 0 4
        Set<String> top5 = stringRedisTemplate.opsForZSet().range(key, 0, 4);
        if (top5 == null || top5.isEmpty()) {
            return Collections.emptyList();
        }
        // 2.解析出其中的用户id
        List<Long> ids = top5.stream().map(Long::valueOf).collect(Collectors.toList());
        String idStr = StrUtil.join(",", ids);
        // 3.根据用户id查询用户 WHERE id IN ( 5 , 1 ) ORDER BY FIELD(id, 5, 1)
        String sql = "select *\n" +
                "from user\n" +
                "where ID in (idS)\n" +
                "ORDER BY FIELD(ID ,idS)";
        sql = sql.replaceAll("idS", idStr);
        List<User> users = new Eql().returnType(User.class).execute(sql);
        // 4.返回
        return users.stream().map(user -> BeanUtil.copyProperties(user, UserDTO.class)).collect(Collectors.toList());
    }


    public List<Blog> queryBlogByUserId(Integer current, Long id) {
        HashMap<String, Object> map = new HashMap<>(3);
        map.put("userId", id);
        map.put("currentPage", (current - 1) * MAX_PAGE_SIZE);
        map.put("pageSize", MAX_PAGE_SIZE);
        return new Eql().select("getBolgOfMe").params(map).returnType(Blog.class).execute();
    }

    public Result queryBlogOfFollow(Long max, Integer offset) {
        // 1.获取当前用户
        Long userId = UserHolder.getUser().getId();
        // 2.查询收件箱 ZREVRANGEBYSCORE key Max Min LIMIT offset count
        String key = FEED_KEY + userId;
        Set<ZSetOperations.TypedTuple<String>> typedTuples = stringRedisTemplate.opsForZSet()
                .reverseRangeByScoreWithScores(key, 0, max, offset, 2);
        // 3.非空判断
        if (typedTuples == null || typedTuples.isEmpty()) {
            return Result.ok();
        }
        // 4.解析数据：blogId、minTime（时间戳）、offset
        List<Long> ids = new ArrayList<>(typedTuples.size());
        long minTime = 0;
        int os = 1;
        for (ZSetOperations.TypedTuple<String> tuple : typedTuples) {
            // 4.1.获取id
            ids.add(Long.valueOf(tuple.getValue()));
            // 4.2.获取分数(时间戳）
            long time = tuple.getScore().longValue();
            if (time == minTime) {
                os++;
            } else {
                minTime = time;
                os = 1;
            }
        }
        // 5.根据id查询blog
        String idStr = StrUtil.join(",", ids);
        String sql = "select *\n" +
                "from blog\n" +
                "where ID in (idS)\n" +
                "ORDER BY FIELD(ID ,idS)";
        sql = sql.replaceAll("idS", idStr);
        List<Blog> blogs = new Eql().returnType(Blog.class).execute(sql);
        for (Blog blog : blogs) {
            // 5.1.查询blog有关的用户
            queryBlogUser(blog);
            // 5.2.查询blog是否被点赞
            isBlogLiked(blog);
        }
        // 6.封装并返回
        ScrollResult r = new ScrollResult();
        r.setList(blogs);
        r.setOffset(os);
        r.setMinTime(minTime);

        return Result.ok(r);
    }
}
